| 摘要 |
PROBLEM TO BE SOLVED: To shorten the working time by one device to hydraulically expand a tube and form a tube inlet piece, and to prevent a joint from being generated between the tube and the tube inlet piece by manufacturing the tube inlet piece from the tube itself. SOLUTION: A tube 3 of a heat exchanger is expanded and fixed into a tube plate 1 by a hydraulic method, and a tube inlet piece provided with roundness is formed out of the same tube 3 by a same device in a same working process. The tube 3 is inserted in a hole of the tube plate 1 and cut to the excessive length. The tube 3 is expanded over the whole depth of a hole 2 by an expanding machine, and the tube 3 is attached to an inner wall of the hole 2. At the same time, a projected tub end part 10 is directed to the tube plate 1 by another hydraulic forming apparatus 11 provided with an arch-shaped part 12, and the tube end part 10 is pressed on a mandrel 4 of an expanding machine to a trumpet shape. |
